The primary focus of the Animal Resource Core will be to facilitate the use of the murine model of autoimmune arthritis for the study of autoimmunity and inflammatory responses in the rheumatic diseases. We will 1) emphasize both the training and education of RDRCC investigators, young investigators, and established investigators new to-the rheumatic diseases in the utilization of this model; 2) introduce modern approaches to multi-color immunofluorescence and flow cytometric analysis of the cells involved in autoimmune and inflammatory responses; and 3) assist investigators with the breeding, backcrossing to CIA susceptible strains, and screening of genetically altered strains of mice. The centralization of these functions within this core will greatly facilitate the RDRC investigator's studies of rheumatic disease processes through the establishment of consistent and reproducible, quality controlled procedures and reagents.